Method of and apparatus for paper making



Dec. 1, 1931 P E 1,833,910

METHOD OF "AND APPARATUS FOR PAPER MAKING Filed Ma'rch 29, 1950 6Sheets-Sheet 1 (fizz/Mir 039M072 W152? 6 She ets-Sheet,

Filed March 29. 1930 Dec. 1, 1931. H. PARKER METHOD OF AND APPARATUS FORPAPER MAKING 6 Sheets-Sheet 5 Inuuuuun L.

nun-unann- Dec. 1, 1931. H. PARKER METHOD OF AND APPARATUS FOR PAPERMAKING 6 Sheets-Sheei Aw Filed March 2 9. 1950 v RN \\\\\Q h NW2.

Dec. 1, 1931. H. PARKER METHOD OF AND APPARATUS FOR PAPER MAKING FiledMarch 29, 19750 6 Sheets-Sheet 5 Fllllillllllllllll .Illlllllllll.

Dec. 1, 1931. H. PARKER I METHOD OF AND APPARATUS FOR PAPER MAKING FiledMarch 29, 1930 6 Sheets-Sheet e Patented Dec. 1, 1931.

UNITED STATES PATENT OFFICE HOWARD PARKER, OF BERLIN, NEW HAMPSHIRE,ASSIGNOR TO BROWN COMPANY, OF

BERLIN, NEW HAMPSHIRE, A CORPORATION OF MAINE METHOD OF AND APPARATUSFOR PAPER MAKING Application filed Harch 29, 1930. Serial No. 439,984.

This invention relates to improvements in paper making machinery of thetype WhlCh employs one or more cylinder molds for the formation of thepulp sheet. While most of the individual improved features areapplicable to machines having a single cylinder mold, they arehereinafter descrlbed and are illustrated on the drawings as embodied ina multi-ply paper making machine. It is ordinarily desirable to producepaper having the maximum strength and uniformity obtainable with thekind and-quantity of pulp employed. The strength of a sheet of paperdepends to a large extent upon the arrangement and the interfelting ofthe pulp fibers of which it is composed. The uniformity of the sheetdepends on the proper distribution of the fibers therein. A furtherdesirable feature in paper for most uses is substantially equal strengthin all directions. A sheet of paper made in the usual way on a cylindermold machine is more easily torn lengthwise than across, this being dueto a directional effect given to a considerable percentage of the fibersby the motion of the surface of the mold in the pool of pulp from awhich the web is formed. Many attempts have been made to overcome thetendency of a cylinder mold to pick up a web with a predominantproportion of fibers lying in the direction of travel of the sheet, butas far as applicant is aware, these attempts have been unsuccessful inproducing a practical and eflicient mechanism for the purpose. Accordingto the present inventlon, mechanism is provided which causes theformation of a web on a cylinder mold with the fibers uniformlydistributed therein both as to quantity and arrangement, the fibers alsobeing thoroughly interfelted.

In attaining the results desired, use is made of the well known tendencyof fibers in an aqueous suspension flowing through a pipe or in achannel to arrange themselves in line with the direction of flow, due tothe variation in speed of flow between water adjacent to the surface ofthe pipe in contact therewith and the middle of the stream. To this enda stream of pulp suspension is caused to flow adjacent to the c lindermold and parallel to the axis thereo so as to arrange a large proportionof the fibers in the stream in a direction parallel with the axis of themold. Pulp from this stream is deposited on the mold in such away thatmost of the fibers which have been aligned with the stream parallel tothe axis of the mold retain this directional characteristic so thatinthepulp web formed on the mold, a considerable proportion of thefibers are disposed transversely with respect to the web. Thisstrengthens the web and the resulting paper sheet against longitudinaltearing.

The strength of paper made according to the invention may also beaugmented by forming a number of very thin webs of pulp and thenpressing and felting these webs together into a single sheet.Interfelting be-' tween the plies is promoted by bringing the pliestogether under such conditions that the water in the plies passesthrough the sheet substantially in one direction only. In the formationof plies for a paper sheet, one or more plies may be made with apredominating number of fibers extending in the lengthwlse direction ofthe sheet, others of the plies havlng predominating numbers of fibersextendlng transversely. Such sheet may be made uniformly resistant totearing in any direction.

For uniformity of distribution of pulp in each ply, a speciallyconstructed cylinder mold is provided, this mold being also adapted foruse with an internal suction device for a prellminary draining andcompacting of the pulp web on the mold. The provision of asuction boxwithin the cylinder mold necessitates the construction of the mold inthe form of a hollow cylinder which must. be sufficiently strong tosupport the wire screen on its surface against the suction, and mustalso present to the under surface of the wire screen narrow supportingmembers so as to avoid.

outer faces free from wire marks from the mold. This is accomplished bythe manner in which the several plies are transferred from the molds tothe sheet. The mechanism Figure 2.

is furthermore provided with various adjustable features by which thecharacteristics of the several plies may be modified in various ways.

For a more complete understanding of the invention, reference may be hadto the description thereof which follows, and to the illustrationthereof on the drawings, of which,

Figure 1 is a side elevation of multi-ply paper making mechanismembodying the invention.

Figure 2 is a transverse section of one unit of the mechanism shown inFigure 1, the section being taken on the line 2-2 of Figure 8.

Figure 3 is a section on the line 3'3 of Figure 4 is a fragmentarytransverse section of one of the cylinder molds.

Figure 5 is a section of the same.

Figure 6 is a perspective view of avpulp vat.

Figure 7 is a fragmentary longitudinal section of mechanism within acylinder mold.

Figure 8 is an end elevation of one of the paper making units, part ofthe figure being a section on the line 8-8 of Figure 1.

Figure 9 is an end elevation of a paper making unit viewed as indicatedby the line 99 of Figure 1.

Figures 10 and 11 are sections taken res ectively on the lines 1010 and11-11 of igure 8.

Referring to the drawings in detail, Figure 1 represents in elevation aportion of a multi-pl paper making machine, three cylinder mol s 20being shown. The machine may include a larger or smaller number ofcylinder molds as desired. The molds 20 are are each supplied with asuitable pulp vat 21, the molds and vats being conveniently supported asby a pair of horizontal beams 22. As shown, the vats 21 are so locatedas to present the stock therein to an upper quadrant of each of themolds, the pulp web which is picked up by each mold being deposited on asuitable felt 23 which travels in a generally horizontal path beneaththe molds and may be tangent to one or more of them. In the mechanismillustrated in Figure 1, the felt 23 is tangent to two of the threecylinder molds 20 but passes underneath the third mold, on theleft handside of the figure, without touching it, the web from this mold beingtransferred first to a felt 24 from which it is picked up by the felt23. This arrangement may be employed when it is desired to produce asheet'of paper having both of its surfaces smooth. As the pulp isdeposited in a Web on' any of the cylinder molds 20, the face of-the webwhich is against the mold itself'is wire-marked thereby, the oppositefragmentary longitudinal face of the web being smooth. It is obviousfrom Figure 1 that where the felt 23 is tangent to a mold 20 the webfrom that mold is deposited on the felt with the wire-marked surface up.By transferring the final ply first to the felt 24 and then to the felt23, the ply or web is inverted so as to be deposited on the felt 23 withits smooth side up. This produces a paper sheet with both faces smooth.

In forming a multi-ply sheet of paper from a number of thin individualwet plies, it is important to promote maximum interfelting of the fibersin the successive plies if strength is desired in the ultimate product.Relatively great strength may be obtained by uniting the successiveplies 1n such a manner that the moisture therein flows through the sheetin a single direction. This draws the fiber ends into effectiveinterfelted rela tion which ties-together the successive plies andproduces a strong coherent sheet. In order to bring about suchinterfelting between the plies, a suitable suction box 25 is providedagainst the under face of the felt 23 at the point where the felttouches the circumference of the cylinder mold 20 or the felt 24. Thusthe passage of the water in the several plies is maintained in adownward direction through the sheet in the process of its formation,this unidirectional flow promoting a high degree of interfelting betweenthe fibers of the successive webs or plies. In order to consolidate thesheet after each ply has been added thereto, a suitable press roll 26may be provided to press upwardly against the surface of the cylindermold 20 so that the felt 23 with the pulp sheet thereon is squeezedbetween the roll 26 and the mold 20. The pressure of the roll 26 againstits mold may be regulated as by a system of levers 30, 31 linkedtogether as at 32, the lever 31 having an adjustable weight 33 thereon.Each suction box 25 may be resiliently held adjacent to the surface of acylinder mold 20 as by a suitable lever 34 which may be pivoted as at35, one end of the lever engaging a lower face of the box 25 as at, 36,the opposite arm of the lever being provided with an ad'ustable weight37. The limit of approach 0 the suction box toward the cylinder mold 20may be conveniently regulated as by a set screw 38. The felt 24,

after picking up the pulp web from the cylin-.

der 20, ma pass around a suitableroll 41 which is a jacent to or incontact with the cylinder 20. In this form of construction the pressroll 26 engages the roll 41 rather than the cylinder m'old 20, and thesuction box 25 is likewise adjacent to the roll 41. This arrangementresults in a transfer of the pulp web from the felt 24 to the felt 23when the former is passing about the roll 41. The felt 24 may thereuponbe led upwardly to a suitable tank 42 where it may be washed as by jetsfrom a spray pipe 43, after which the felt is led back into contact withthe cylinder mold 20 by suitable guide rolls.

The pu p vat by which pulp stock is supplied to the surface of eachcylinder mold is illustrated in Figures 2, 3 and 6. As shown the pulpmay be supplied through a suitable supply pipe 50 into a compartment 51at one end of the vat. In this compartment it flows downwardly andenters a horizontal channel 52 wherein a considerable body of pulp flowsin a direction parallel to the axis 0 the cylinder m'old, this channelextending from one end of the mold to the other. The wall 53 of thechannel 52 which is nearest tothe' tions 54. The wall 53 is preferablyplaced about an inch from the surface of the cylinder mold 20, but thisdistance may be varied as desired. The other end of the channel 52 theapertures 54 is made sufficient to produce opens into an uptake 55through which the stock fiows into an upper compartment 56 and spillsover a dam .57 into a discharge compartment 58 whence it leaves the vatas at 59. The stream of stock flowing through the channel 52 tends toarrange a large proportion of the fibers therein in the direction offlow of the stream, that is, in a direction parallel to the axis of thecylinder mold. As

and-against the surface of the cylinder mold,

where they interfelt with one another to form the web of pulp which issubsequently transferred to the felt 23.

The combined cross sectional area of all a rapid flow of pulptherethrough. The distance of such flow from the channel 52 to thesurface of the cylinder mold illustrated in Figure 2 is approximatelyone inch, so that there is insufficient time for any considerable numberof the fibers to turn to dif ferent directions, and a large majority ofthe fibers are drawn against the surface of the mold in a directionwhich is substantial- 1y parallel to the axis of the mold, that is,transverse with respect to the web itself. Thus the sheet of pa erformed with plies laid in this manner as a high resistance tolongitudinal tearing. If desired, the directional strengthcharacteristics of the fin- .be'1conveniently.adjusted, as by a vertical:movable board 61' which acts as an adjustable crest for the dam 57. Theboard 61 may be adjustable by any suitable mechanism such as a pair ofuprights 62 each having a rack 63 meshing with a pinion 64, the pinionsbeing mounted on a common shaft 65.

In order to control. the characteristics of the pulp webs deposited onthe several cylinder molds 20, it is desirable to supply each cylindermold with internal suction mechanism by which suction may be applied toa suitable arc of the inner surface of the wire screen. Since thecylinder mold must necessarily be rotated, the presence of suctionapparatus within the mold necessitates the construction of the mold inthe form of a hollow cylinder. As the suction is applied to the upperportion of the cylinder mold, it adds materially to the gravitationalstresses on the mold itself so that the mold mustbe strongly made to.avoid sagging in the middle or other distortion under the stressesimposed thereon. The cylinder mold must also be formed with a surfaceagainst which the Wire screen may be supported, the supporting surfaceof the mold being preferably no Wider at any point than approximatelyone-sixteenth of an inch. If any of the areas of support are materiallywider than that, the depositing of pulp on the areas of screen over suchportions is retarded so that the thickness of the pulp web isnonuniform. According to the invention a cylinder mold is provided whichis not only strong and rigid, but which has, a supporting surface forits Wire screen such that the thickness of the web deposited on thescreen is uniform from end to end of the mold. a

As shown in Figures 2, 4 and 8, the cyl' inder mold comprisesa series ofrings placed side by side and hold together by a series of tie bolts 71.Each ring consists of a flat portion in a plane perpendicular to theaxis of the mold. Extending from one face of this flat ring are a numberof vanes 72 and 73, these vanes extending from the inner edge of thering to the outer edge in a direction which is preferably at an angle tothe radial direction. As indicated in Figure 4, the vanes 72 alternatewith the vanes 73, the former each having an enlarged portion 74 whichis bored to receive a tie-rod 71 therethrough. When the rings 70 areassembled to form a hollow c lindrical shell, the vanes of each aresuitably aligned with the corres onding vanes'of the others so that thetie-r0 s 71 extend from end to end of the cylinder through a successionof correspon ing vanes in the, several rings and the corresponding setsof vanes 72'and 73 form substantially continuous partitions extcndingfrom one end of the mold to the other. Between such successivepartitions are channels 75 passing from the outer surface of thecylinder mold to the inside of the mold. The outer surface of thecylinder is covered with the customary screen 80 offine wire. To sup ortthis screen smoothly in'the form of a su stantially true cylinder, aseries of supporting ribs 81 is provided. As indicated in Figure 5, eachof the vanes 72 and 73 is slotted at its outer end to receive the ribs81, with the outer edges of the ribs flush with the outer edges of thevanes. The ribs 81 ma conveniently be formed by winding helica ly andedgewise a single strip of flat wire around the cylinder mold insuccessive notches in the vanes, this wire being retained in place bysoldering, brazing, or in any convenient manner. The wire 81 ispreferably about one-fourth to five-sixteenths. of an inch wide andone-sixteenth of an inch thick, this being suflicient to support thewire "screen 80 without causing any thin places in the web deposited onthe screen, as it is wound so as to present one edge outward asindicated in Figure 5.

Suction may be applied to a portion of the mold as by mechanismillustrated in Figures 2 and 8. In the cylindrical chamber within themold, a suction chamber may be formed by a partition member 90 whichextends from one end of the mold to the other and which terminates atone end in a suction pipe 91. This partition may be stiffened by asuitable longitudinal rib 92.- As shown in Figure 2, the partition 90extends from side to side of the chamber within the mold, the partitioncontacting with the inner surface of the mold through suitable packingstrips 93 against which the inner surface of the mold rubs as the moldrot-ates. Sincethe downward drag on the cylinder produced by the suctionis considerable. especially when the cylinder is of considerable length,bearing members may be provided to support the middle portion of thecylinder. These may be in the form of a pair of longitudinally extendingribs 94 which are supported by the partition member 90 and which bear onthe inner surface of the mold bv means of packing members 95. It isdesirable to be able to regulate the characteristics of the pulp webpicked up by the cylinder mold by-rotationally adjusting the partitionmember 90 about the axis of the cylinder. To this end the suction pipe91. which is integral with the partition 90 and projects from the end ofthe cylinder, as shown in Figure 8, is provided with a lever arm 96which is connected as by a screw 97 to a fixed nut 98 mounted on theframe 22, as shown in Figure 1, so that by manipulation of a hand wheel99 the lever arm 96 may be the packing angularly adjustable and which isprovided 7 with an extension 106 in threaded engagement with a screw107. The latter may be fixed against axial movement, as by a suitablebearing 108, and may be rotatable by a convenient hand wheel 109 toraise or lower the suction apparatus within the cylinder..

Provision is made for producing pulp webs of di li'ercnt widths bydeckle members 115 which are adjustable length-wise of the cylindermold. When the deckles are moved to change the width of the web to bedeposited on the cylinder mold, it is desirable to adjustcorrespondingly the length of the suction chamber within the cylindermold. To this end the end walls of the suction chamber are madeadjustable as illustrated in Figures 7, 8, 10 and 11. The suctionchamber itself extends from one packing strip 93 to the other. Ina-segment between these two strips is a plate 116 having a packing 117ofresilient material around it, this packingbeing adaptedto fit againstthe inner surface of the cylinder mold 20 and alsoagainst the uppersurface of the partition member 90. As

shown in Figure 7, this plate 116 and the packing 117 are movablelongitudinally of the cylinder. For. adjusting movement of the plate116, it is provided with an extension 118 the end of which is inthreaded engagement with a screw 119 which may be rotated by a sprocketwheel 120 to move the plate 116 and packing 117 toward or from the endof the cylinder mold. Since the packing 117 must be loose in order topermit such adjusting movement, means are provided for expanding andcontracting the packing. For this purpose the packing is mounted betweenthe plate 116 and an opposing plate 125, these plates being providedwith conical surfaces adapted to press against the packing 117 and tocause the packing to bulge outwardly when the plates move toward eachother. Such motion may be provided by a tubular member 126 which isinternally threaded on a portionof the extension 118, as at 127. Thetubular member,126 is in splined engagement with a tubular extension130, the latter being provided with an operating wheel 131 which may bea hand wheel or a sprocket wheel. The splined engagement of the tubularmemher 126, with its extension 130, permits these two members totelescope when the plate 116 is drawn outwardly toward the end of thecylinder mold. A key or spline 132, mounted in the tubular member 126,slides in a suitable slot 133. \Vhen it is desired to move the plate 116and the packing 117 in accordance with an adjustment of thecorresponding deckle 115, the wheel 131 is rotated to move the plate 125away from the plate 116 and thus to permit the packing 117 to contractaway from the cylinder mold. Thereupon the wheel 120 is rotated in adirection suitable to move the plate 116 to the desired location,whereupon the wheel 131 is operated in a reverse direction to expand thepacking memher 117 into contact withthe cylinder mold 20. The sprocketwheels 120 and 131- may be suitably connected by chains. (not shown) toother hand-operable wheels more conveniently located.

The characteristics of the pulp 'web deposited on the cylinder mold mayfurther be controlled by the provision of a mask 140 (Figure 2). Thismay be in the form of a waterproof sheet, one end of which is wound ona; suitable roll 141, the free end portion passing under a guide block142 and resting against the surface of the cylinder mold 20. By raisingor lowering the free end, the area of loading surface of the cylindermold may thus be regulated.

In the lower portion of the pulp vat 21, a separate compartment 145 maybe provided, this compartment containin a spray p1pe 146 adapted toproject jets o washing water against the surface of the cylindrical moldin order to clean the wire screen just before it is exposed to the poolof pulp stock within the vat. A suitable apron 147 may be provided tocatch the pulp which is thus washed from the surface of the screen. Thewash water which is projected through the screen and through thecylinder shell may be caught in a suitable compartment 150 within themold, from which it may be led away by suitable channels. In the lowerportion of the chamber within the cylinder mold a suitable arcuate plate151 may be provided to catch white water which may flow through the moldfrom the vat before the material comes in contact with the first packingmember 93. Thus the. mechanism. may be adjusted so as to cause the pulpto be depositedquickly on the mold under the action of gravity alone.This results in an even, well distributed sheet and avoids wild. webs.After the initial depositing of pulp on the mold, suction is appliedwhile the web is still in 'contact with the pool of pulp stock. Thissuction condenses the deposited web and also tends to thicken anyadventitious thin spots. The suction is maintained transfer to the felt23.

from until the mold reaches the second packfrom suction until it reachesthe point of I claim: 1.111 the art of paper making, a method ofsupplying pulp stock to a rotating cylinder mold, which comprisesinducing a freeflow of stock in a stream adjacent to the cylinder moldand parallel to the axis there of, shielding said stream fromdisturbance by the motion of the mold, and drawin stock laterally to thesurface of the mol from adjacent points of the stream.

2. In the art of paper making, a'method of forming a. pulp web on arotatingcylinder mold, which comprisesinducing a free flow of pulp stockin a stream adjacent to the mold and parallel to the axis thereof,shielding said stream from disturbance by motion of the mold, drawingstock laterally 111g member 93, whereupon the web isfreed from thestream to a portion of the surface of the mold adjacent thereto,maintaining a body 'of pulp stock against the next adjacent portion ofthe mold surface in the direction of its motion, and applying suctionwithin the surface portion of the mold in contact with said body ofpulp.

3. Apparatus of the class described comprising a cylinder mold, a pulpstock vat adjacent to said mold, and a duct for pulp stock within saidvat extending substantially parallel to the axis of said mold, said ducthaving a perforated side-wall close to a portion of the surface of themold, said vat having supply and discharge passages communieating withthe ends of said duct whereby a stream of stock may flow longitudinallythrough the duct.

4. Apparatus of the class described comprising a cylinder mold, a pulpstock vat adjacent to an upper quadrant of said mold, and a duct in saidvat extending substantially mrallel to the axis of said mold, said ducthaving an arcuate perforated side wall following the. shape of theadjacent surface of the mold and spaced about an inch therefrom, saidvat including means for maintaining a pool at a substantially constantlevel above said duct and communicating with one end thereof whereby aregulated fluid pressure is maintained in the duct.

5. Apparatus of the class described comprising a cylinder mold, a pulpsto' k vat against a portion of said mold, a perforated curved platewithin said vat and spaced a short substantially uniform distance fromthe adjacent surface of the mold, and means within said vat fordirecting a flow of pulp along theface of said plate remote from themold in a direction substantially parallel to the axis of the mold.

6. Apparatus of the class described comprising a cylinder mold, a pulpstock vat against a portion of said mold adapted to present a pool ofstock to a portion of the surface of the mold a curved plate in said vatuniformly spaced from the adjacent surface of the mold, said plateextending above the normal surface level of said pool of-stock andhaving perforations through the lower portion thereof, and meansincluding said vat for maintaining a flow of stock along the perforatedportion of said plate on the side remote from the mold and in adirection parallel to the axis of the mold.

7. Apparatus of the class described comprising a cylinder mold, a pulpstock vat I against a portion of said mold adapted to present a pool ofstock to a portion of the surface of the mold, a curved plate in saidvat uniformly spaced from the adjacent sur- 7 face of the mold, saidplate extending above the normal surface level of said pool of stock andhaving perforations through the lower portion thereof, means formaintainin a flow of stock along the perforated portlon of said plate onthe side remote from the mold and in a direction parallel to the axis ofthe mold, and an adjustable flexible shield extending upwardly from thebottom of said vat adjacent .the surface of the mold.

8. Apparatus of the class described comprising a cylinder mold, a pulpstock vat against'a portion of said mold adapted to present a pool ofstock to a portion of the surface of the mold, a curved plate in saidvat uniformly spaced from the adjacent surface 7 of the mold, said plateextending above the normal surface level of said pool of stock andhaving perforations through the'lower por- I tion thereof, means formaintaining a flow of stock along the perforated portion of said plateon the side remote from the mold and in a direction parallel to the axisof the mold, and means for applying suction from within to a portion ofthe surface of the mold extending from below the surface of said pool ofstock to a point beyond the point of emergence of the mold surface fromsaid pool. I

9. Apparatus for making multi-ply paper, which comprises a plurality ofcylinder molds in a series, a'pulp stock vat against an upper quadrantof each said mold, a traveling felt disposed beneath said molds andtangent to at least the first of said series of molds to receivedirectly therefrom the web of pulp formed thereon, an auxiliary felt inquadrant of each said mold, a felt trave to the mold up, and means fortransferring the web on the last of said molds in the series to saidfelt with the face of the web formed next to the mold down.

In testimony whereof I have aflixed my signature.

H'OWARD PARKER.

